The Research And Application Of 3D Ice Accretion Measurement Method On Wings

In a certain flight environment,the aircraft wings easily to freeze.Because the wing is a larger windward area of the aircraft,it is one of the most easy to produce the ice accretion.Ice accretion can affect the flow of airflow and change the streamline shape of the wing,and destroying the flow pattern of the wing.It would cause resistance increased,lift dropped,critical angle of attack reduced and so on.In a word,wing icings have the effect of the flight safety.Due to the different of speed of flight and atmospheric conditions,such as the water content,the size of the water droplets,the degree of cooling and the freezing speed and so on,the wing surface will form different ice accretion,such as horn ice,roughness ice,streamwise shape.It is important and significance to get the ice accretion under certain conditions.It provides an important technical support for the aircraft deicing and anti-ice design.There are a number of currently used options for documenting ice accretion in icingwind-tunnel testing.They range from pencil tracings to mold and casting methods.These two methods are contact measurement methods.They are low efficiency,long cycle and low accuracy.With the development of measurement technology,three-dimensional measurement method is more and more used in the measurement of ice accretion,which has high precision,high efficiency,good operability and so on.In this paper,based on the deeply study and research about the three-dimensional measurement method on ice accretion,the author has used the structured light 3D measurement to completed ice accretion measurement in the ice wind tunnel.Here are the main work this article include:(1)The study of ice accretion on the airplane,introduce the aircraft icing phenomenon and of the major research methods at home and abroad.(2)The study of the measurement system's three coordinate system and the conversion among them,the principle of pinhole imaging,the distortion of camera lens and the measurement principle of the system.(3)The study of difficulties and key points of 3D ice accretion measurement method in low temperature environment(-20 ?).(4)The 3D ice accretion measurement is finished in the ice wind tunnel,which used the structured light 3D measurement method.Finished the scan data processing procedure and analysis.